Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 191834 AFDOKX Area Forecast Discussion National Weather Service New York NY 234 PM EDT Sat Aug 19 2017 .SYNOPSIS... One cold front will pass east of Long Island this morning, while another passes through tonight. High pressure will follow from Sunday through Tuesday. A frontal system will move across from Wednesday into Wednesday night, followed again by high pressure. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Shortwave trough aloft over the Great Lakes this morning will pivot toward the region late today. A weak surface trough lingers, with a cold front approaching from the west late this afternoon and tonight. A much drier air mass in the low/mid levels will advect/mix down, except right along the coast where sea breezes will keep dewpoints closer to 70. With shortwave energy still well west and mid-level warming, forcing and instability have been limited, with only sct Cu. Cu have built up more along the north shore of Long Island, so a brief isolated shower is possible there. High temps still on track to reach 85-90, highest NYC metro and the interior CT river valley. Residual southerly swells of 3-4 ft @ 6 sec period this morning favor a high rip current risk for the eastern Long Island ocean beaches, and a moderate risk farther west. These swells will continue to slowly subside into this evening.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
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Vigorous upper level shortwave trough approaches this evening and moves across tonight. At the surface, a weak cold front will moves across. High-res models have continued to signal convection approaching western sections, with sct coverage possible before sunset mainly in Orange County. An isolated shower is still possible thereafter into the evening mainly for the lower Hudson Valley, NE NJ, and NYC. Zonal upper flow ensues for Sun into Mon. At the surface, high pressure builds in from the west Sunday into Sunday night, with mostly sunny, dry, and still quite warm conditions expected, with high temps only a shade lower than those of today. As the high sinks south and east, heat and humidity will build build into the region Monday into Tuesday. Highs will generally be well into the 80s to lower 90s on Monday, and possibly lower to mid 90s for Tuesday. Models are indicating potential for isolated diurnal convection on Tuesday as instability increases and convectively induced vort energy rotates around the upper ridge. Low predictability at this point.
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&& .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... Decent model agreement with shortwave energy digging into the Great lakes Tue into Tue Night and then towards the NE US on Wed. An associated frontal system will bring the next chance for organized shower and tstm activity late Tue into Wed. A significant cool down then looks to follow for the end of the week. The models have been very consistent with this signal, although the exact magnitude of the cold airmass remains in question. It would not be totally surprising to see some lows in the furthest outlying areas touch the upr 40s next weekend. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/...
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A cold front will move across the region tonight, with high pressure building in for Sunday. VFR through the TAF period. A few showers and/or thunderstorms are possible with the frontal passage tonight. The best chance appears to be at KSWF around 00Z, although confidence is too low to include in the TAF at this time. Any showers could result in a brief period of MVFR visibilities. SSW flow will continue at coastal terminals this afternoon with WSW flow elsewhere. A few gusts to around 15 kt are possible at the city terminals late this afternoon into early this evening. Winds become light and variable at most terminals outside of the city tonight before returning out of the NW Sunday morning behind the cold front. .OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... .Sunday-Tuesday morning...VFR. .Tuesday afternoon-Wednesday...A chance of showers and thunderstorms with MVFR or lower conditions possible. SW gusts to 15-20 kt. .Thursday...VFR.
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&& .MARINE...
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Winds and seas will increase ahead of a cold frontal passage late Tuesday into Wednesday. Ocean seas may reach advy levels Tuesday night, and continue in southerly swells into Wed night.
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&& .HYDROLOGY... Impacts from potential showers and thunderstorms Tuesday into Wednesday are uncertain at this point. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Rip Current Risk until 8 PM EDT this evening for NYZ080- 081. NJ...None. MARINE...None. && $$ SYNOPSIS...Goodman/NV NEAR TERM...Goodman/NV SHORT TERM...NV LONG TERM...JMC/NV AVIATION...FEB MARINE...Goodman/NV HYDROLOGY...NV

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